The present invention relates to a magnetic data storage device, and more particularly to a write pole for a perpendicular writer having improved control over critical dimensions.
As magnetic recording storage densities continue to progress in an effort to increase the storage capacity of magnetic storage devices, magnetic transition (i.e., bit) dimensions and critical features of the recording device are being pushed below 100 nanometers (nm), particularly for writers that operate on the principle of perpendicular recording. This decrease in critical dimensions presents a significant challenge to the manufacture of devices such as perpendicular writers due to the corresponding decrease in the error tolerance margin associated with production of the devices. For example, in a perpendicular writer, the dimensions of the write pole break point (WP BP) and the front shield throat height (FS TH) are critical dimensions defined during the slider lapping process, and typically are targeted to be approximately 100 nm or less. These dimensions have traditionally been defined by two independent photolithography layers in wafer fabrication, which results in an error (3-sigma) of about 50 nm, five times larger than an exemplary 10% tolerance margin. This range of variation results in a poor yield of devices that meet specifications. A design and/or process that reduces the error associated with the production of devices such as these would be a desirable improvement to the state of the art.